Process of and apparatus for the manufacture of lower-boiling hydrocarbons from higher-boiling hydrocarbons



Dec. 4 1923. 1,476,091

A. M. MCAFEE PROCESS OF AND APPARATUS FOR THE MANUFACTURE OF LOWER BOILING 1919 2 Sheets-Sheet 1 HYDROCARBONS FROM HIGHER BOILING HYDROCARBONS Filed Dec.

A Chicane Dec. 4 1923. 1,476,091

A. M. MCAFEE PROCESS OF AND APPARATUS FOR THE MANUFACTURE OF LOWER BOILING HYDROCARBONS FROM HIGHER BOILING HYDROCARBONS Fi [390- 15, 1919 2 Sheets$heet 2 aywmatm wane so m. marlin, or POR-T ARTHUR, rnxas, assrsnon TO GULF nErININe oom- P, or PITTSBURGH, PENNSYLVANIA, A coRPonA'rIoN or TE PROCESS OF AND APPARATUS FOR THE MANUFACTURE OF LOWER-BOILING HYDRO- CARBONS FROM HIGHER-BOILIN G HYDROCARBONS.

Application filed. December 15, 1919. Serial No. 344,933.

To all whom it may concern:

Be it known that I, ALMER M. MCAFEE, a citizen of the United States, residing at Port Arthur, in the county of Jefferson and State of Texas, have invented certain new and useful Improvements in Processes. of and Apparatus for the Manufacture of Lower-Boiling Hydrocarbons from Higher- Boiling Hydrocarbons, of which the following is a specification.

This invention relates to processes of and apparatus for the manufacture of lower boiling hydrocarbons from higher boiling hydrocarbons, and it comprises boiling anhydrous aluminum chlorid, liquefied by oil, in the presence of higher boiling oils, and distilling off lower boiling oils produced, forming from aluminum ch orid in the oil a viscous, gummy mass, kneading such mass to present successive surfaces thereof to the higher boiling oil. and, advantageously, to

the vapors evolved, continuing the heating as the mass hardens, and mechanically disintegrating it as it hardens, the disintegrated material being withdrawn from the still, continuously or from time to time; and it further and more specifically comprises a method of producing lower boiling oils, for instance, gasoline, 0r asoline and kerosene, from higher boiling oi s with the aid of anhydrous aluminum chlorid to obtain a good utilization of said oil and said chlorid, wherein said oil and said chlorid are boiled together in a still provided with refluxing devices, in such a manner as to deliver vap 'ors to the condenser not exceeding a temperature of about 350 F.. the charge of oil and chlorid during the distilling operation being kneaded, as well as agitated and in addition being subjected to a comminuting or grinding action by movable heavy elements within the still; and it further comprises a still provided with suitable firing means, partial and final condensers, and means in the still for agitating kneading and comminutin the contents, such still being advantageous y horizontal and such means being advantageously a longitudirnally mounted stirrer and weights or other mechanical means in the still arranged to be operated upon by the stirrer in. such a manner that they may knead and pound the contents of the still; all as more fully hereinafter set forth and as claimed.

Most of the heavier mineral oils can be converted into gasoline or kerosene, or into gasoline and kerosene, and similar relatively low boiling oils, of excellent quality and with excellent yield by being boiled with anhydrous aluminum chlorid in a suitable still and under suitable conditions. The boiling mixture in the still should be constantly stirred or agitated during the operation and the hot vapors should be cooled down from the temperature at which they leave the boiling mass to a temperature not exceeding about 350 F. prior to their delivery to a final condenser.

The relatively low boiling oils so obtained are 0 high grade, being saturated, sweet and water-white products, whatever the quality of the oil under distillation. By cooling down the vapors as described aluminum chlorid is prevented from going forward and clogging up the condenser, making the condensate acid, etc. Suitable refluxing means are provided to return vol- As so far stated, the operation is substantially that described in my 00 ending application Serial No. 792,615, fi ed September 30, 1913.

On adding a small amount, say, 5 per cent of anhydrous aluminum chlorid to a charge of high boiling oil in a still and heatin the chlorid forms with part of the oil a airly mobile heavy dark brown to black liquid underlying the main body of oil and substantially immiscible therewith. While the chlorid dissolves or combines with a certain amount of the hydrocarbons of the charge, the mutual solubility of the oil and chlorid is quite limited. At a temperature 100". or so below the normal boiling point of the oil under treatment the mass boils freely, giving ofi" vapors which, operating in the described manner, can be condensed to give gasoline or gasoline and kerosene. Ordinarily, the distillation is conducted in a cheesebox type of still provided with powerful stirring means, stlrring being necessary not 'only to emit free evolution of vapors from the c lorid mass, but to prevent bakin on the bottom of the still.

As disti lation goes on, the la er of mobile, molten aluminum chlorid, w ich can be at first freely stirred and disseminated till through the overlying body of oil, becomes stifi', gummy and stick During this phase, the stirrer which at first requires butlittle power to operate it, encounters a greater resistance. Later, the gummy mass begins to become coky and brittle and the stirrer moves more freely.

The reason for this progressive change in consistency from thinness and mobility through stiflness and Stickiness to hardness and brittleness, probably resides in changes undergone by the hydrocarbons dissolved by or associated with the aluminum chlorid, rather than in any, change in the latter. With relatively heavy oils, such, for instance, as gas oil and solar oil, and with the ordinary speed of distillation, the mass becomes viscous and gummy so as not to be capable of free movement after about 36 hours of operation. With oils lighter in gravity than solar and gas oil, such, for in stance, as lterosene stock, from which in ordinary refinery practice kerosene is made, the change to the viscous and gummy con sistency occurs later in th operation. Observation shows that when the mass has become viscous and gummy, its character as a mass is not much affected by the stirrer; the mass is not broken up and disseminated through the-oil body as in the preceding stage nd the surface of the mass exposed to the oil does-not change rapidly. The mass tends to move with the stirrer, agitating the oil but itselii not being much agitated. Th stirrer serves in this stage mainly to scrape the bottom of the still and prevent adhesion of carbon to the bottom of the still. The mass moves as a body through or with the oil, and is not disseminated therethrough. Later when the mass becomes harder and more brittle it is broken up to some extent by the stirrer and in this phase there is again a mixture of oil and mass 'to a certain extent. It is of course however a-matter or a mixture of fragments and liquid rather than of a much increased exposure ofactiv aluminum chlorid to the oil. 'lhe fragments contain much chlorid which is not freely exposed to contact with the oil. During this hardening phase, as stated, the power required is diminished somewhat. lln previous practice it has been rarely desirable to carry the hardening operation' too far; it has been desirable to interrupt'distillation at a time ,when the mass is oi such consistency s permits ready withdrawal from the still. At this time however the aluminum chlorid present has not lost all its oil converting power. With some thin oils this time is later in arriving than with heavier viscous oils, such as solar oil;

' and, to, this extent, there is customarily better utilization of activity up to the time of interruption the thin oils than with the thicker; but the discharged eolry raraoer residues nearly always presents activity. As heretofore pointed out, the aluminum chlorid exists as such throughout the entire operation, in fact when the operation is carried on to such a stage that the residue is a hard. coky, brittle mass, unaltered aluminum chlorid may be recovered therefrom. From the first to the last, the aluminum chlorid, in so far as it is not broken up by moisture, sulfur, oxygen or other impurities in the oil, remains apparently was changed. It can be extracted by water, as hydrated aluminum chlorid at any time between th first formation of a molten liquid and the final formation of coke. Nevertheless its converting activity diminishes with use, whatever he the reason, and can be pushed to an end. But because of the considerations stated this end is not quite reached in practice, the stills being discharged at a time when the coky material removed still contains active chlorid mechanically enclosed.

As the speed of distillation, in a measure,

depends upon the rate at which fresh surfaces of the aluminum chlorid or mixture are exposed for escape of vapors and for action upon the main oil body and since economy of operation requires full exhaustion of the activity of the chlorid, it is desirable that during the viscous stage means he adopted giving" constantly changing surfaces to the aluminumchlorid mass and that the operation be so conducted that the activity can be exhausted while producing a final product which can be easily taken from the still. it is an object of the present invention to achieve these ends; operating in such a manner that it is possible to continue the distillation until the aluminum chlorid becomes not only colry and brittle but is reduced to fine hard grains with a comparatively great surface of exposure to' the oil. thus utilizing the chlorid to agreater extent in a distilling operation than heretofore. it operate in such a manner during the distillation that the viscous and gummy mass is more effectively dispersed through the body of oil and the vapors in the still. lln so doing ll stir the aluminum chlorid mixture in the high boiling oil until the viscous and gurmny mass is formed and then disseminate the viscous and gummy mass-through the oil and, advantageously, through the vapors in the still, and continue the distillation operation in this way until a colty mass is formed. which is then broken up or comminuted. The mass is broken up by mechanical means in the still into a tine. grained material which can be easily Withdrawn.

@ne way of accomplish ng this is the provision of a horizontal still provided with substantially centrally longitudinally mounted stirrer, having blades which will come in close proximity with the interior walls. This stirrer, during the first stage, agitates the aluminum chlorid and the oil and, during the second stage when the viscous and gummy mass forms, kneads such mass in the presence of the oil, repeatedly exposing new surfaces of the mass to the oil-and carrying the mass into the vapor space of the still. The viscous and gummy mass is repeatedly-kneaded, distended and pulled in the presence of the oil and vapors. I further provide mechanical abrading, grinding and comminuting means which may be placed in the still pr'or to the commencement of the operation, or added or placed in function at the time the viscous mass forms or begins to harden. Since these means may advantageously assist in the kneading operation, I usually put them in the still with the inital charge. These means may be of such material as to efi'ectively assist in distributing the heat throughout the mass and they may well be a plurality of weighty objects, such as steel, iron or bronze balls, or any heat resisting heavy objects suitable for grinding and the like. If these grinding means are present during the formation and existence of the viscous and gummy mass, they mingle therewith and assist the stirrer in kneading and distending it. As the mass hardens these grind ng means become-free and are carried and tumbled around in the still, against the walls thereof and against the parts of the stirrer, and serve to grind the hardening mass to a degree of fineness commensurate with their size, weight and number. The hardened mass is ground to a fine material adapted for easy withdrawal from the still which is important in commercial operation. The grinding means serve to keep the still and the stirrer clean and bright and free from adhesions so that no special clean-' ing after discharging'is needed.-

In the accompanying drawings, showing one form of a specific ,embod ment of apparatus useful in carrying out my process and within the purview of my invention- Fig. 1 is a view, partly in longitudinal section and partly in elevation, of a still w th its accoutrements, and

Fig. 2 is a vertical section along line 2 -2 of Fig. 1. 7

Referring to the drawings, element 1 indicates the base or foundation of the still, and 2 the fire box thereof. The still is .fired in any of the usual ways, such, for instance, as by a spray of fuel oil and steam through the burner 3, the oil being admitted through valved pipe 4 and the steam through valved pipe 5. and the air supply finding entrance at 6. The firewall or bridge 7 serves to direct the heat towards the bottom of the still and may also be used as a support for the still at a point about the center, as indilow boiling oils.

cated at 8. As many supports as are necessary may be provided along the length of the still.

The gases and products of combustion find exit through the flue 9 and thence to the stack 10. The bridge wall 7 is of fire brck or like material but the foundations 1 may well be of building brick or other ordinary structural material. However, the interior i lined with .firebrick or other fire resisting materal 11, and the top of the still is suitably insulated by means of firebrick, asbestos compositions, or other insulating material, indicated as 12.

At a'point along the length of the still,

for instance, at about its center, I provide a series of condensers into which the vapors,

pass. Prelim nary cooling chamber 13 is in communication with the still through pipe 14 and in communication with air cooled that the temperature of the vapor at that point may be taken. In practice the temperature at this point is not allowed to exceed about 350 F. Vapors condensing at higher temperature than that named flow back to the still and the body, of oil under treatment, those condensed in 13 through pipe 14, and those condensed-in 15 and in 17, through the backtrap 21. The backtrap 21 is provided with the usual trap 22 for the purpose of mak'ng a liquid seal and preventing the vapors from the still going directly to condensers '15 and 17. This backtrap line 21 may or may not be beat insulated as the exigencies of the particular case dictate. The air-cooled condenser or coolingchambers to which reference hasbeen made serve the important function of condensing aluminum chlorid vapors'or vapors of aluminum chlorid-hydrocarbon compounds carried forward during the distilla. tion. Aluminum chlorid volatilizes at about 365 'F. and I have found that if I control the fires under the still in such a. way as to not send forward tothe final water-cooled condenser for condensation therein vapors substant ally above 350 F. no aluminum chlorid or aluminum chloridh drocarbon compounds are present in the distillate or in the vapors going past the final air-cooled condenser. And the distillate thus secured will consist entirely of The still .is provided with inlet pipe 23, valved at 24 and in communication with a source of high boiling oil supply, and aluminum chlorid mixed with oil to a magma for convenience in handling may also be supplied to the still through this line. The still is also provided at thebottoimand preferably at one end, with the draw-off pipe 25, provided with cock 26. The disintegrated material usually in the form of powder is withdrawn with residual oil through this line. This pipe leads to cooling coils and to a final repository for the coky residue. The still is sealed by means of end covers 27 and 1 28, suitable bolts 29 being provided. Journaled in the still and through the end covers is the longitudinal shaft 30, having a bearing at 31-and passing through the stuifing b02132 on the, cover 28, packing 33 being provided for the stuffing box. The shaft is similarly journaled through the cover 27 and the bearing 34. The shaft is operated by means of motor 35 driving shaft 36 in communication with shaft 30 through suitable zreduction gears diagrammatically shown at 3 The shaft 30 is provided with a. plurality of arms 38, having longitudinal paddles 39 bolted thereto by means of bolts 40. T have shown two paddles 39 but may of course use any desired number. The still is provided with a number of grinding elements 41 here shown as steel balls of sufficient size to be carried by the paddles 39. These balls may be introduced into the still prior to the commencement of the distillation operation, or they may be introduced at a later period through the hopper 42 suitably valved at 43. Ordinarily I supply a suflicient number of these balls to lie' in close contact on the bot tom of the still throughout its length in one layer. The operation of the still is obvious from the foregoing description.

In operation. about 5 per cent of aluminum chlorid calculated on the operating still capacity, is introduced admixed with asmall proportion of oil through inlet 23, and the stirrer started in rotation. The higher boiling oil to be converted into lower boilingoil is then introduced through inlet 23 iii amount equalling about 75 per cent of the.

said capacity'of the apparatus. The fire is started and the mixture thus heated until it boils. The distillation is controlled by observation of the thermometer or other temperature indicating device and the fire so regulated that the vapors in air-cooled condenser at a point just prior to the water cooled condenser shall not register a terhperature above 350 F. Vapors condensing at higher temperature than that indicated and volatilized aluminum chlorid, or volatilized aluminum chlorid-hydrocarbon compounds, are returned to the. still through the back trap 22 or the line 14. The higher boiling ar ner mass of aluminum c-hlorid becomes viscous and gun'imy, the stirrer paddles 39, assisted by the balls 41, extend this viscous mass throughout the body of oil and present it to the vapor at the top of the'still, thoroughly kneading the mass. As the viscous mass hardens, the balls 41 break free and are repeatedly lifted up and dropped by the paddles 39,- falling against portions of the pad-i dies and the stirrer and against the walls of the still, crushing, disintegrating and. abrading the hardened and hardening mass. At the end of the operation. when the activity of the aluminum chlorid has diminished to such an extent as to warrant charging with fresh aluminum chlorid, the cook 26 on the discharge pipe is opened and the residual oil is discharged together with the finely disintegrated coky residue. All the oil in the still may be drawn off with fine coke or merely enough of it to flush the coke forward. tageously continued in rotation during this tapping operation. Since the material in the still is hot, the coky residue and accom- The stirrer may be advanpanying oil are preferably discharged through a cooling coil to prevent iginition of the oil upon coming in contact with the atmosphere. The oil tapped off and the coky residue are allowed to remain quiescent and separated oil drawn off from the coky residue which settles to the bottom. The coky residue is then treated to recover aluminum chlorid therefrom in any known way. such, for instance, as by the process described and claimed in my Patent 1,099,096, or in my copending application Serial No. 284,347 The separated oil may be used in admixture with a charge of new oil in the described process. i. e., returned to the still; or it may be treated with fresh aluminum chlorid in the manner described in my Patent 1,277,329,

or as described in my Patent 1,127,465. lit 4 but a. small part of the residual oil. I .am-

thus able to leave in the still a. volume of unconverted higher boiling oil to form apart of the next charge. Examination of the still. after discharging the contents, shows clean, bright surfaces on the interior walls and stirrer.

- 'Of course, it is to be understood that the drawing}; accompanying this application is merely indicative of a type of apparatus ll may use. Many other types are applicable. I may employ a battery of tills of any number and arranged to operate some of them out of phase with the others as regards supplying oil and aluminum chlorid and Withdrawing the coky residue and the'residual oil, with the result that in such a plant I can make a continuous run.

In converting oils by distillation with aluminum chlorid it is of course desirable to be able to run as longas possible on a given charge of chlorid, not only for the sake of economy of chlorid but because changing the charge-involves a loss of time and of heat. This object is accomplished in the present invention since the coky matcrial is reduced to a fine grained material, easily stirred up through the oil and presenting a large surface of exposure thereto, thereby giving a maximum opportunity for exhaustion of the activit of the chlorid. In good practice under t e present invention the ultimate granular coky material is as fine as wheat or finer; being fine enough to flow readily as a fluent mass with oil. This renders it possible to discharge a still by merely-opening a cock, reducing the loss of time and heat in changing a charge to the minimum. No stoppage to chip out and clear away hard coky adhesions is necessary, the action of the grinding balls keeping the whole interior of the still bright and clean.

In the use of the structure shown, as the aluminum chlorid material thickens and becomes gummy it is carried up one wall of the still forming, more or less an angle-ofrepose or angle-of fiow surface exposed to the oil and to the vapor space in the still. During this period there is a kneading action in the sense of a mixing or flowing ac tion which is constantly exposing fresh surfaces of the gummy material for release of vapors and for contact with oil. Later as the material becomes still more gummy it is carried around the walls as an annulus, it wraps itself around the stirring members as clinging masses, etc. During this period there is a comparativel great surface exposure of the gum. Still later as the mass becomes brittle and breaks up into constantly finer fragments there is a constantly increasing surface exposure. During the first stage of development of gumminess, the balls are carried up by the stirrer and fall back through the mass, stringing it out. A. little later when the gumminess is greater, the sound of falling balls is no longer heard though they are still in movement and continue in movement, more or less, throughout this stage. They are carried around the still in the gum; and they break away from it from time to time, but their fall is cushioned by the thick material. The balls are very eflicient in kneading in this stage. When the material finally becomes brittle the noise of the falling and pounding balls once more becomes audible.

What I claim is 1. In the manufacture of lower boiling oils from higher boiling oils wherein a converting agent is used which agent during the progress of the reaction becomes of a sticky and gummy character, the step of kneading such agent at this time to constantly change its surfaces and repeatedly expose fresh surfaces to the body of oil undergoing conversion.

2. In the manufacture of lower boiling oils from higher boiling oils wherein a converting agent is used which agent during the progress of the reaction passes through successive stages of stickiness and gumminess and of hardness, the process which comprises kneading it during its sticky and gummy stage and grinding it during its hard stage.

3. In the distillation of oils with aluminum chlorid the process of quickening the action of the chlorid on the oil and enhancing the extent of utilization of such chlorid which comprises kneading the chlorid with the oil when its consistency becomes gummy and comminuting it in the presence of the oil after it becomes brittle, such comminution being continued until the chlorid mass is reduced to a finely granular condition.

4. In distilling oils with aluminum chlorid the process which comprises mechanically comminuting the coky mass resulting from the aluminum chlorid in the latter stages of distillation during such latter stages.

5. In the distillation of oils with aluminum chlorid the process which comprises kneading during the distillation the gummy masses formed from the aluminum chlorid so as to expose constantly changing surfaces of the gummy material.

6. In the distillation of oils with aluminum chlorid the process which comprises kneading during the distillation the gummy masses formed from the aluminum chlorid and after such masses become too brittle for kneading performing mechanical comminution thereon.

7. In the distillation of oils with aluminum chlorid the process which comprises maintaining grinding balls in motion within the still duringthe distillation operation.

8. In the manufacture of lower boiling oils from higher-boiling oils wherein a converting agent is used which agent during the progress of the reaction passes through successive stages of stickiness and gumminess and of hardness, the process which comprises kneading the agent in the first stage in the presence of the oil to extend said agent and string it out, and during the second said stage, subjectin said agent to the pounding action of faling grinding elements.

9. In the manufacture of lower boilin oils from higher boiling in a horizontal stil e uipped with a horizontal stirrer and w erein a converting agent is used which a'gent during the reaction becomes sticky and gummy and then hard in successive stages, the process which comprises lifting by means of said stirrer a plurality of grinding elements, entangling the same in the mass during the sticky and gummy stage whereby the grinding elements fall through the mass and extend it in the presence of the' grinding elements located therein and actuated by the stirrer.

11. A horizontal still provided with a longitudinal stirrer and a plurality of weighty grinding elements arranged to be lifted and dropped by said stirrer.

12. In apparatus for the conversion of higher boiling oils into lower boiling with the aid of aluminum chlorid the combination of a still, stirring and lifting means therein and a plurality of steel balls adapted to be lifted by the lifting elements.

13.111 apparatus for the conversion of higher boiling oils into lower boiling with the aid of'aluminum chlorid the combinaancer tion of a. cylindrical still body having a vapor outlet, condensin means connected to said vapor outlet, a horizontal shaft extending through said still body and journaled in the ends thereof, horizontal blades carried by said shaft and arranged in proximity to and to sweep the still walls and a plurality of metal balls Within said still of a size adapting them to be carried upward by said horizontal blades.

14. In the conversion of higher boiling oils into lower boiling oils by distilling such high boiling oils with aluminum chlorid, the process which comprises conducting such distillation in a suitable still in the presence of rinding elements adapted to comminute t e hard coky mass resulting from the aluminum chlorid in the later stage of the distillation, the comminution being carried to a stage where the coky material is reduced to a free flowing finely granular condition and at the close of distillation withdrawin'g such finely granular material from the still with the aid of sufiicient oil to form with it a fluent body easily flowing through the pipes, valves, etc.

In testimony whereof, I affix my signature.

ALMER M. MoAlFEE. 

